1. Field of the Invention
The present invention relates to a circuit connection structure for an electric connection box and a circuit forming method.
2. Description of the Related Art
Electric connection boxes for the multipoint connection of various kinds of the electric equipment such as wire harnesses for automobiles are used for reasonable and economical multipoint connection of wirings with the multipoint connection points provided at one point. Various types have been developed according to the trend toward the higher density of wire harnesses, depending on the kind of the automobile or the application.
Bus bars to be stored in the electric connection box are provided by punching out plural kinds of bus bars from a hoop material with a press mold, cutting up tub terminals each from the pattern part of each bus bar, providing an insulation plate between the bus bars, and storing the same in the electric connection box.
However, since the above-mentioned bus bars have different shapes in the pattern part so that they need to be punched out with a press mold dedicated to each of them, problems such as a high production cost and the lack of flexibility due to difference in the bus bar pattern part shape for the electric connection boxes for the same kind of automobiles but of different grades arise.
Japanese Patent Application No. 11-180649, corresponding to U.S. Pat. Ser. No. 09/520,186, describes a connection structure for bus bars, capable of electrically connecting the bus bars on both surfaces by disposing a vertical direction bus bar on one surface of an insulation plate and disposing a lateral direction bus bar on the other surface of the insulation plate, fitting with a through hole of the insulation plate a dent part of at least one of the bus bars at an appropriate position of the intersection part of the bus bars on both surfaces, and welding the dent part in the state contacting with the bus bar on the surface facing thereto.
According to the related art, since the bus bars can be provided by disposing the common straight vertical direction bus bar and lateral direction bus bar in a combination, and welding the dent part at the intersection part for connecting the upper layer and lower layer bus bars, unlike the conventional configuration, the bus bars need not be provided by punching out with dedicated press molds for different pattern shapes so that the production cost can be reduced. Moreover, since any bus bar pattern shape can be dealt with only by changing the position of the dent part, effects such as drastic cutback of the number of the circuit design steps as well as capability of dealing with design change derived from a slight circuit modification quickly so as to improve the flexibility can be achieved.